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 Dec31 awarded Popular Question Jul11 revised Nonlinear FEM and FindRoot improved formatting Jul10 revised Nonlinear FEM and FindRoot typos Jul10 comment FindRoot: getting number of iteration thanks again for your reply. You are right, here link you can find more about SYS1. It is related with a FEM code. Is that enough for you? Jul10 comment FindRoot: getting number of iteration thanks for your suggestion. I'll look at this documentation Jul10 comment FindRoot: getting number of iteration If I substitute EvaluationMonitor with StepMonitor, I don't know what I get. I my case, FindRootPlot gives 3 steps and 25 residuals. The use of EvaluationMonitor gives back 24, instead StepMonitor gives 1 (I got the same using A) Reap[FindRoot[Sin[x] == Cos[x], {x, 0}, EvaluationMonitor :> Sow[x]]], B) Reap[FindRoot[Sin[x] == Cos[x], {x, 0}, StepMonitor :> Sow[x]]]and C) FindRootPlot[Sin[x] == Cos[x], {x, 0}] (FindRootPlot gives 5 steps and 5 residuals) Jul10 comment FindRoot: getting number of iteration The code iter = Reap[FindRoot[SYS1[XX, UU, F1, fun1] == 0, {UU, U0}, EvaluationMonitor :> Sow[UU]]] works, but I obtain how many times the residuals is computed. Jul10 comment FindRoot: getting number of iteration how can I apply your code at my case? My function is like F[x,par] = 0. I tried with iter = Reap[ FindRoot[SYS1[XX, @UU, F1, fun1] == 0, {UU, U0}, EvaluationMonitor :> Sow[UU]]], but it does not work Jul10 asked Nonlinear FEM and FindRoot Jul10 asked FindRoot: getting number of iteration Jun3 accepted How to set initial guess in NDSolve Jun3 comment How to set initial guess in NDSolve Thanks very much for your reply and sooty for this delayed reply, but I got some troubles in real life! Your answer seems to fit what I wanna do. I'll try with this! Jun3 comment How to set initial guess in NDSolve Sorry for this delayed reply, but I got some troubles in real life! When you solve a nonlinear differential equation using a fem approach (or simply a nonlinear system using a newton method) you need a guess initial value for "each" point before starting your loop cycle. I want to do something similar using NDSolve May30 comment How to set initial guess in NDSolve Thanks again for your reply. Using a shooting method, you give a "suggestion" only for the value of the function and its derivative a fixed point. I'd like to pass "all points" of the initial guess (for instance, a linear function between my bcs). Is it possible to do that? May30 comment How to set initial guess in NDSolve @Szabolcs Thanks for your reply, you are right, I adjusted my code. I'd like to know how to add the initial guess without using shooting method. May30 revised How to set initial guess in NDSolve added 2 characters in body May30 asked How to set initial guess in NDSolve Dec14 comment How to solve a stiff nonlinear second-order ode? @ Michael:if you have time, should you have a look at the "original" problem? mathematica.stackexchange.com/questions/38798/… Dec13 comment How to solve a stiff nonlinear second-order ode? @ Michael thanks again for your answer, it is extremely accurate! Dec13 accepted How to solve a stiff nonlinear second-order ode?